Herd reproduction is the most important indicator of the economic efficiency of the industry. Assisted reproductive technology, especially artificial insemination, is widely used in dairy farming. When using this method, tens of thousands of cows and heifers are inseminated with the seed of a single bull, therefore, the used biomaterial must meet high requirements, since the use of low-quality sperm products can lead to multi-million losses. The reproductive performance of breeding bulls depends on numerous biotic and abiotic factors. breeding bulls depends on numerous biotic and abiotic factors. The purpose of the study the influence of meteorological factors on the biological usefulness of sperm from bulls of different breeds. A multidimensional dispersion analysis of the effect of temperature and geomagnetic activity on the quality of spermatozoa was performed. The results of multidimensional dispersion analysis show that the combination of temperature factors with geomagnetic activity has a statistically significant effect on the content of spermatozoa with abnormal movement in the fresh seed and on the activity of spermatozoa (p<0,05). Geomagnetic activity (K-index ≥5,0) leads to an increase in the proportion of spermatozoa with pathological morphology. This trend was observed regardless of the season of the year. During the summer period, on days with increased geomagnetic activity, the content of spermatozoa with pathology increased by 66% compared to the period when there is no magnetic disturbance. Under the influence of geomagnetic activity, the proportion of spermatozoa with abnormal movement increased – such spermatozoa in the ejaculate contained an average of 10,2%, depending on the season and temperature, this indicator varied from 6 to 21,5%. High geomagnetic activity and temperature lead to an increase in the proportion of spermatozoa with a violation of the structure of nDNA.
The allelotypes of the analyzed populations of Black-and-White cows bred in the Tver Region and the Republic of Ingushetia have been reported. The strong effects of breed and trends for its production parameters in the analyzed Black-and-White cows bred in the Tver Region and the Republic of Ingushetia, rather than the ecological impact, are revealed. The frequency of the «bad» A1 allele at a beta-casein locus was higher in the animals in the Tver Region, comprising 0,56, while the “normal” A2 allele was reported at a frequency of 0.44. Quite similar results were obtained for the analyzed cows in the Republic of Ingushetia. Thus, the frequencis of the «bad» A1 allele and the normal allele comprised 0,52 and 0,48, respectively. The findings based on the survey results can indicate that the selective breeding activity in the Tver Region herd requires a shift towards increasing the occurrence of the favourable A2 alleles due to selecting the bull sires with the target genetic traits.
The article is devoted to the issue of heritability of the age of puberty in female sables. The paper provides data on the percentage of daughters in mothers of different degrees of sexual maturity, the coefficient of heritability of this trait is determined. The article discusses the issue of the possibility of breeding to increase the reproductive capacity of replacement sable females by age of puberty.
The article presents a comparative characteristic of the skin in long-haired cat breeds based on the use of morphological research methods, including anatomical preparation, light microscopy of histological sections, micromorphometry and statistical analysis of the obtained digital data. The general patterns and breed characteristics of the skin in long-haired cats have been established, taking into account its anatomical and topographic features. An inverse relationship was found between the thickness of the epidermis and the thickness of the hair cover in the studied animals, regardless of breed. The specific glomerular design of collagen structures of the dermis was established in all long-haired cat breeds. It has been shown that the depth of the hair follicles and the density of the hair are determined by the topical features of the skin.
The Rabies – a viral disease characterized by severe damage of the nervous system. The analysis of data from the Rospotrebnadzor for 4 years (from 2015 to 2018) on the varmint of animals with rabies in four regions of the Central Federal District with different population densities is carried out. The main carriers of rabies virus in the region are the red fox, raccoon dog, stray dogs and cats; the role of other species is not so significant and rarely exceeds 1% of the total number of animals with suspected rabies. It has been established that in areas with a low population (Tver region) the role of a raccoon dog in rabies transfer can be even more significant than red foxes. To reduce the incidence of human rabies, constant monitoring and regulation of the numbers of foxes and raccoon dogs in the wild, as well as stray dogs and cats, is highly required. Consequently, we consider the current tendency to remove stray dogs from their habitats, their sterilization and return to urbocenosis insufficient; sterilized dogs will remain a source of rabies in populated locations.
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